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    <title>copfac</title>
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    <center>Scilab Function</center>
    <div align="right">Last update : April 1993</div>
    <p>
      <b>copfac</b> -  right coprime factorization</p>
    <h3>
      <font color="blue">Calling Sequence</font>
    </h3>
    <dl>
      <dd>
        <tt>[N,M,XT,YT]=copfac(G [,polf,polc,tol])   </tt>
      </dd>
    </dl>
    <h3>
      <font color="blue">Parameters</font>
    </h3>
    <ul>
      <li>
        <tt>
          <b>G</b>
        </tt>: <tt>
          <b>syslin</b>
        </tt> list  (continuous-time linear system )</li>
      <li>
        <tt>
          <b>polf, polc</b>
        </tt>: respectively the poles of <tt>
          <b>XT</b>
        </tt> and <tt>
          <b>YT</b>
        </tt> and the poles of <tt>
          <b>n</b>
        </tt>  and <tt>
          <b>M</b>
        </tt> (default values =-1).</li>
      <li>
        <tt>
          <b>tol</b>
        </tt>: real threshold for detecting stable poles (default value <tt>
          <b>100*%eps</b>
        </tt>)</li>
      <li>
        <tt>
          <b>N,M,XT,YT</b>
        </tt>: linear systems represented by <tt>
          <b>syslin</b>
        </tt> lists</li>
    </ul>
    <h3>
      <font color="blue">Description</font>
    </h3>
    <p>
      <tt>
        <b>[N,M,XT,YT]=copfac(G,[polf,polc,[tol]])</b>
      </tt> returns a right coprime factorization of <tt>
        <b>G</b>
      </tt>.</p>
    <p>
      <tt>
        <b>G = N*M^-1</b>
      </tt> where <tt>
        <b>N</b>
      </tt> and <tt>
        <b>M</b>
      </tt> are stable, proper and right coprime.
    (i.e. <tt>
        <b>[N M]</b>
      </tt> left-invertible with stability)</p>
    <p>
      <tt>
        <b>XT</b>
      </tt> and <tt>
        <b>YT</b>
      </tt> satisfy:</p>
    <p>
      <tt>
        <b>[XT -YT].[M N]' = eye</b>
      </tt> (Bezout identity)</p>
    <p>
      <tt>
        <b>G</b>
      </tt> is assumed stabilizable and detectable.</p>
    <h3>
      <font color="blue">See Also</font>
    </h3>
    <p>
      <a href="../elementary/syslin.htm">
        <tt>
          <b>syslin</b>
        </tt>
      </a>,&nbsp;&nbsp;<a href="lcf.htm">
        <tt>
          <b>lcf</b>
        </tt>
      </a>,&nbsp;&nbsp;</p>
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